Operating a three phase device using single phase power
AssigneeOtis Elevator Company
InventorsIsmail Agirman, Vladimir Blasko, Christopher Czerwinski
Life of this patent
Estimating the term…
Abstract
A powering arrangement (32, 34) for a device (30, 22) that normally operates on three phase power has the capability of operating based upon single phase power. One disclosed technique includes estimating a direct component based upon a measured voltage across the leads coupled with the single phase power supply. The quadrature component is estimated based upon a numerical derivative of the direct component. The direct component is also provided to a current regulator in a feed forward control manner, which minimizes error.
Claims11
A device for providing power to an elevator machine, comprising
- a converter interface configured to be between a power source and an elevator machine controller, the converter interface providing an output current to the controller, the converter interface comprising:
- a phase locked loop portion having three phase inputs, all three of the phase inputs being coupled to a lead of three phase input power if three phase input power is available from the power source, one of the phase inputs being set at zero and two others of the three phase inputs each being coupled to a lead of single phase input power if only single phase input is available from the power source, the phase locked loop portion using an estimated direct component and an estimated quadrature component based on the single phase input power when the single phase input power is available, the estimated direct component comprising a measured voltage of the single phase power;
- a proportional integral regulator that provides an indication of a current for eliminating error between a desired current level provided to the controller and an output current level from the converter interface;
- and
- a current regulator portion that uses (i) an output from the phase locked loop portion combined with an output from the proportional integral regulator and (ii) the estimated direct component as a feed-forward input, the current regulator portion allowing the converter interface to provide three phase output power to the elevator machine controller if either the three phase input power or the single phase input power is available.
A method of providing power to an elevator machine, comprising
- using a converter interface between a power source and an elevator machine controller to provide three phase output power to the elevator machine controller if either three phase input power or single phase input power is available from the power source;
- using the three phase input power from the power source when three phase input power is available;
- and
- using the single phase input power from the power source when only single phase input power is available including
- determining an estimated direct component and an estimated quadrature component based on the single phase input power, the estimated direct component comprising a measured voltage of the single phase power;
- determining a sinusoidal reference in phase with single phase voltage from the power source based on the estimated direct and quadrature components;
- determining a current for eliminating error between a desired current level provided to the controller and an output current level from the converter interface;
- and
- regulating current provided to the elevator machine controller based on (i) the determined sinusoidal reference combined with the determined current for eliminating error and (ii) the estimated direct component as a feed-forward input.
Dependencies are inferred from the claim text.